The invention relates to a control method for a system having an inverter with a direct current connection, a direct current source, and an additional direct current source or a direct current sink, wherein the direct current source and the additional direct current source or the direct current sink are connected in parallel to the direct current connection of the inverter. Furthermore, the invention also relates to such a system.
DE 10 2012 109 420 A9 discloses a system with an inverter which has a DC/DC converter and a DC/AC converter, as well as a direct voltage link to which the DC/DC converter and DC/AC converter are connected. This inverter has a direct current connection; that is, the input-side connection for the DC/DC converter. The system has a direct current source in the form of a photovoltaic system (designated a photovoltaic generator in the document). Furthermore, the system has a component in the form of a battery that can be used both as an additional direct current source (when drawing power from the battery) as well as a direct current sink (when charging the battery). The photovoltaic system and the battery are connected in parallel to the direct current connection of the inverter (at the input of the DC/DC converter). With the system known from DE 10 2012 109 420 A9, it is furthermore provided to connect the battery to the direct voltage link. This makes it possible to charge the battery directly with energy generated by the PV system by circumventing the DC/DC converter. DE 10 2012 109 420 A9 addresses the issue of which operating states are for charging the battery directly by means of the PV system, and which operating states are for charging the battery by means of the direct voltage link.
Against this background, the invention addresses the task of increasing the efficiency of operating such a system.